Browse
Submit Data
Databases
API
Help

Dataset Information

39 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Compression of X-ray Free Electron Laser Pulses to Attosecond Duration.

ABSTRACT: State of the art X-ray Free Electron Laser facilities currently provide the brightest X-ray pulses available, typically with mJ energy and several hundred femtosecond duration. Here we present one- and two-dimensional Particle-in-Cell simulations, utilising the process of stimulated Raman amplification, showing that these pulses are compressed to a temporally coherent, sub-femtosecond pulse at 8% efficiency. Pulses of this type may pave the way for routine time resolution of electrons in nm size potentials. Furthermore, evidence is presented that significant Landau damping and wave-breaking may be beneficial in distorting the rear of the interaction and further reducing the final pulse duration.

SUBMITTER: Sadler JD

PROVIDER: S-EPMC4645159 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Attosecond Coherence Time Characterization in Hard X-Ray Free-Electron Laser.

Project description:One of the key challenges in scientific researches based on free-electron lasers (FELs) is the characterization of the coherence time of the ultra-fast hard x-ray pulse, which fundamentally influences the interaction process between x-rays and materials. Conventional optical methods, based on autocorrelation, are very difficult to realize due to the lack of mirrors. Here, we experimentally demonstrate a novel method which yields a coherence time of 174.7 attoseconds for the 6.92 keV FEL pulses at the Linac Coherent Light Source. In our experiment, a phase shifter is adopted to control the cross-correlation between x-ray and microbunched electrons. This approach provides critical diagnostics for the temporal coherence of x-ray FELs and is universal for general machine parameters; applicable for wide range of photon energy, radiation brightness, repetition rate and FEL pulse duration.

| S-EPMC7136262 | biostudies-literature

Shot-by-shot characterization of focused X-ray free electron laser pulses.

Project description:X-ray free electron lasers (XFEL) provide intense and almost coherent X-ray pulses. They are used for various experiments investigating physical and chemical properties in materials and biological science because of their complete coherence, high intensity, and very short pulse width. In XFEL experiments, specimens are irradiated by XFEL pulses focused by mirror optics. The focused pulse is too intense to measure its coherence by placing an X-ray detector on the focal spot. Previously, a method was proposed for evaluating the coherence of focused pulses from the visibility of the diffraction intensity of colloidal particles by the speckle visibility spectroscopy (SVS). However, the visibility cannot be determined exactly because the diffraction intensity is integrated into each finite size detector pixel. Here, we propose a method to evaluate the coherence of each XFEL pulse by using SVS in combination with a theory for exact sampling of the diffraction pattern and a technique of multiplying the diffraction data by a Gaussian masks, which reduces the influence of data missing in small-angle regions due to the presence of a direct beamstop. We also introduce a method for characterizing the shot-by-shot size of each XFEL pulse by analysing the X-ray irradiated area.

| S-EPMC5770435 | biostudies-literature

In situ single-shot diffractive fluence mapping for X-ray free-electron laser pulses.

Project description:Free-electron lasers (FELs) in the extreme ultraviolet (XUV) and X-ray regime opened up the possibility for experiments at high power densities, in particular allowing for fluence-dependent absorption and scattering experiments to reveal non-linear light-matter interactions at ever shorter wavelengths. Findings of such non-linear effects are met with tremendous interest, but prove difficult to understand and model due to the inherent shot-to-shot fluctuations in photon intensity and the often structured, non-Gaussian spatial intensity profile of a focused FEL beam. Presently, the focused beam is characterized and optimized separately from the actual experiment. Here, we present the simultaneous measurement of XUV diffraction signals from solid samples in tandem with the corresponding single-shot spatial fluence distribution on the actual sample. Our in situ characterization scheme enables direct monitoring of the sample illumination, providing a basis to optimize and quantitatively understand FEL experiments.

| S-EPMC5768711 | biostudies-literature

Photoelectron diffraction from laser-aligned molecules with X-ray free-electron laser pulses.

Project description:We report on the measurement of deep inner-shell 2p X-ray photoelectron diffraction (XPD) patterns from laser-aligned I2 molecules using X-ray free-electron laser (XFEL) pulses. The XPD patterns of the I2 molecules, aligned parallel to the polarization vector of the XFEL, were well matched with our theoretical calculations. Further, we propose a criterion for applying our molecular-structure-determination methodology to the experimental XPD data. In turn, we have demonstrated that this approach is a significant step toward the time-resolved imaging of molecular structures.

| S-EPMC4570188 | biostudies-other

Structural dynamics in proteins induced by and probed with X-ray free-electron laser pulses.

Project description:X-ray free-electron lasers (XFELs) enable crystallographic structure determination beyond the limitations imposed upon synchrotron measurements by radiation damage. The need for very short XFEL pulses is relieved through gating of Bragg diffraction by loss of crystalline order as damage progresses, but not if ionization events are spatially non-uniform due to underlying elemental distributions, as in biological samples. Indeed, correlated movements of iron and sulfur ions were observed in XFEL-irradiated ferredoxin microcrystals using unusually long pulses of 80 fs. Here, we report a femtosecond time-resolved X-ray pump/X-ray probe experiment on protein nanocrystals. We observe changes in the protein backbone and aromatic residues as well as disulfide bridges. Simulations show that the latter's correlated structural dynamics are much slower than expected for the predicted high atomic charge states due to significant impact of ion caging and plasma electron screening. This indicates that dense-environment effects can strongly affect local radiation damage-induced structural dynamics.

| S-EPMC7156470 | biostudies-literature

Resolving molecular diffusion and aggregation of antibody proteins with megahertz X-ray free-electron laser pulses.

Project description:X-ray free-electron lasers (XFELs) with megahertz repetition rate can provide novel insights into structural dynamics of biological macromolecule solutions. However, very high dose rates can lead to beam-induced dynamics and structural changes due to radiation damage. Here, we probe the dynamics of dense antibody protein (Ig-PEG) solutions using megahertz X-ray photon correlation spectroscopy (MHz-XPCS) at the European XFEL. By varying the total dose and dose rate, we identify a regime for measuring the motion of proteins in their first coordination shell, quantify XFEL-induced effects such as driven motion, and map out the extent of agglomeration dynamics. The results indicate that for average dose rates below 1.06 kGy μs-1 in a time window up to 10 μs, it is possible to capture the protein dynamics before the onset of beam induced aggregation. We refer to this approach as correlation before aggregation and demonstrate that MHz-XPCS bridges an important spatio-temporal gap in measurement techniques for biological samples.

| S-EPMC9490738 | biostudies-literature

Temporal lenses for attosecond and femtosecond electron pulses.

Project description:Here, we describe the "temporal lens" concept that can be used for the focus and magnification of ultrashort electron packets in the time domain. The temporal lenses are created by appropriately synthesizing optical pulses that interact with electrons through the ponderomotive force. With such an arrangement, a temporal lens equation with a form identical to that of conventional light optics is derived. The analog of ray diagrams, but for electrons, are constructed to help the visualization of the process of compressing electron packets. It is shown that such temporal lenses not only compensate for electron pulse broadening due to velocity dispersion but also allow compression of the packets to durations much shorter than their initial widths. With these capabilities, ultrafast electron diffraction and microscopy can be extended to new domains,and, just as importantly, electron pulses can be delivered directly on an ultrafast techniques target specimen.

| S-EPMC2705614 | biostudies-literature

Attosecond electron pulses for 4D diffraction and microscopy.

Project description:In this contribution, we consider the advancement of ultrafast electron diffraction and microscopy to cover the attosecond time domain. The concept is centered on the compression of femtosecond electron packets to trains of 15-attosecond pulses by the use of the ponderomotive force in synthesized gratings of optical fields. Such attosecond electron pulses are significantly shorter than those achievable with extreme UV light sources near 25 nm ( approximately 50 eV) and have the potential for applications in the visualization of ultrafast electron dynamics, especially of atomic structures, clusters of atoms, and some materials.

| S-EPMC2141790 | biostudies-literature

Author Correction: Nanofocusing of hard X-ray free electron laser pulses using diamond based Fresnel zone plates.

Project description:An amendment to this paper has been published and can be accessed via a link at the top of the paper.

| S-EPMC7142139 | biostudies-literature

Attosecond electron bunches from a nanofiber driven by Laguerre-Gaussian laser pulses.

Project description:Generation of attosecond bunches of energetic electrons offers significant potential from ultrafast physics to novel radiation sources. However, it is still a great challenge to stably produce such electron beams with lasers, since the typical subfemtosecond electron bunches from laser-plasma interactions either carry low beam charge, or propagate for only several tens of femtoseconds. Here we propose an all-optical scheme for generating dense attosecond electron bunches via the interaction of an intense Laguerre-Gaussian (LG) laser pulse with a nanofiber. The dense bunch train results from the unique field structure of a circularly polarized LG laser pulse, enabling each bunch to be phase-locked and accelerated forward with low divergence, high beam charge and large beam-angular-momentum. This paves the way for wide applications in various fields, e.g., ultrabrilliant attosecond x/?-ray emission.

| S-EPMC5940694 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data